vvEPA
United States
Environmental Protection
Agency
Air and Radiation
EPA 420-F-96-005
June 1996
Office of Mobile Sources
Environmental
Fact Sheet
Revision of Carbon Monoxide Standard
EPA is proposing to increase the Phase 1 carbon monoxide
emission standard for Class I and II nonroad engines to 519 g/kW-
hr. This standard would apply to new spark-ignition engines at or
below 19 kilowatts used in nonhandheld applications.
EPA is
Petitioned to
Revise Current
Standard
EPA Proposes
Revision of
CO Standard
In July 1995, the Environmental Protection Agency (EPA)
finalized the first phase of national regulations to control
emissions from spark-ignition (SI) engines at or below 19
kilowatts (or 25 horsepower). This regulation, referred to as
"Phase 1," applies to engines manufactured during or after 1997.
In March 1996, Briggs and Stratton Corporation submitted to EPA
a petition requesting reconsideration and revision of the
certification fuel requirements and carbon monoxide (CO)
emission standard for nonhandheld engines. Briggs and Stratton
argues that a correction to the Phase 1 rule is necessary because a
significant percentage of the market cannot achieve the existing
CO standard with the specified fuel in the necessary timeframe.
In response to the petition and after review of test data, EPA is
proposing to increase the Phase 1 CO emission standard for Class
I and II nonroad engines from 469 grams per kilowatt-hour
(g/kW-hr) to 519 g/kW-hr. This standard would apply to new SI
engines at or below 19 kilowatts (25 hp), which are used to power
nonhandheld equipment such as lawnmowers.
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This revision is necessary to address the CO emission difference
between oxygenated and nonoxygenated fuels that was not
reflected in the Phase 1 final rule. This correction would ensure
that the CO standard is achievable and technically feasible for
manufacturers to certify their engine models to the Phase 1
emission standards and make them commercially available for
the 1997 model year.
In addition, EPA is proposing to give the Administrator the
option to permit the use of open crankcases in engines used
exclusively to power snowthrowers. This proposed change will
give EPA the flexibility to allow certain engine manufacturers to
certify engines to be used in snowthrowers without making
technological changes that would severely impair the ability of
the engine to function or that would be economically prohibitive.
EPA Seeks
Public
Participation
EPA invites public comment to this proposed rule. For
instructions on submitting written comments, please see the
Federal Register notice. It is available from the EPA Air and
Radiation Docket by calling 202-260-7548; please refer to docket
number A-96-02.
In addition, the rule is available electronically via the EPA
internet server and via dial-up modem on the Technology
Transfer Network (TTN), which is an electronic bulletin board
system (BBS) operated by EPA's Office of Air Quality Planning
and Standards:
World Wide Web: http://www.epa.gov/OMSWWW
TTN BBS: 919-541-5742 (1200-14400 bps, no parity, 8 data
bits, 1 stop bit); voice helpline: 919-541-5384
For More
Information
For more information on this rulemaking, please call the Office of
Mobile Sources at 313-741-7803 or write to:
US Environmental Protection Agency
National Vehicle and Fuel Emissions Laboratory
Engine Programs and Compliance Division
2565 Plymouth Road
Ann Arbor, MI 48105
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